Introduction: The vulnerable atherosclerotic lesion exhibits the proliferation of neovessels and
inflammation. The imaging modality 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography
(18FDG-PET) is considered for the identification of vulnerable plaques.
Purpose: The purpose of this study was to compare the gene expression of neoangiogenesis
and vulnerability-associated genes with 18FDG uptake in patients undergoing carotid
endarterectomy.
Procedures: Human atherosclerotic carotid artery plaques from symptomatic patients were used
for gene expression analysis by quantitative PCR of vascular endothelial growth factor (VEGF)
and integrin aV and integrin ß3 subunits, genes essential during neoangiogenesis. We also
evaluated the gene expression of CD34, a measure of microvessel density (MVD), as well as
CD68, MMP-9, and cathepsin K, genes of major importance in plaque vulnerability. Gene
expression analysis was compared with 18FDG-PET.
Results: VEGF and integrin aVß3 gene expression did not correlate with 18FDG uptake, whereas
CD34 gene expression exhibited an inverse correlation with 18FDG uptake. Additionally, we
established that markers of vulnerability were correlated with 18FDG uptake.
Conclusions: Neoangiogenesis is not associated with 18FDG uptake, whereas MVD and
markers of vulnerability correlate with 18FDG uptake. The absence of correlation between
markers of neoangiogenesis and 18FDG uptake suggests a temporal separation between the
process of neoangiogenesis and inflammatory activity.